1. Field of the Invention
The present invention relates to a vertical axis wind turbine capable of tipping into the wind and spinning. The blade swept area appears like a pyramidal shaped vain pointing into the wind as it spins on a variably oriented spindle. Because the propeller assembly is shaped like a pyramid rather than a flat disk of blades, individual blades may be supported by struts thus allowing for a wind turbine of much larger size.
2. Brief Description of the Prior Art
Recently there has been renewed interest in using wind as a source of energy. The motivating factors are varied but a few key ones include rising oil costs and desiring more energy independence.
Most existing wind turbines are of the horizontal axis design wherein a horizontal rotor shaft and blade assembly is oriented into the wind by a furling tail which may be computer controlled. In high wind, mechanical controls are used to turn the windmill away from the wind to avoid overdriving the alternator or generator. The size of horizontal axis wind turbines is limited by blade strength as the blades must be self supporting. Vertical axis wind turbines are less common wherein the blades are arranged in a squirrel cage configuration. Vertical designs are less efficient because the blades on the backside of the blade swept area must run upwind to come back around, thereby decreasing the efficiency of the wind turbine. The vertical axis design has an advantage over the horizontal axis design in that the means for utilizing the energy, such as an alternator or pump, may be placed at ground or roof level. Thereby allowing for ease of maintenance and less load requirement on the support tower.
What is needed is a wind turbine that combines the benefits of orienting the rotor assembly to face into the wind while at the same time placing the means for utilizing the energy at ground level.